It sounds like you plan to pay a pro, which is probably best. I painted the topsides several times on my 22ft Venture with some variation in quality. Here's a few things I learned.
Once you paint fiberglass, you will have to keep painting it every few years to keep it nice. Maybe less often for a pro job but I'm pretty sure it will still need some care to keep it nice.
Dark colors are harder to make pretty than light colors.
Spray paint makes a mess. It's virtually impossible to spray without overspray going everywhere. If you spray, you will need to build a tent around the boat. I always wanted to spray but I never had a good place to do the work.
Brushing on the paint by hand works better than I would have thought. Marine topsides paint tends to smooth out and if you're careful and feather the brush strokes, there will be very few brush marks visible. I never found a roller that didn't leave a nasty orange peel. By 'feather' I mean to move your wrist like the Karate Kid did in that old 80s movie. I'm not sure if that's the correct term but you get the idea pretty quick when ya start painting. It takes time to do it nice. If you hurry, there will be a lot of brush strokes visible.
I never painted the whole deck. I would guess that the anti-skid surface would present a few challenges.
Here's a picture of the boat from when I sold it a few years back. Once posted on the internet, all pictures are forever, I guess.
The paint is brushed on, one part Petit Epoxy. The color is Bikini Blue.